Add mac address to the DPDK mapping file

When using mapping file with mac address, mapping logic will try
to fetch the mac address of the interface, which will fail. Storing
the mac address also in the DPDK mapping file so that we can satisfy
mapping logic.

Closes-Bug: #1619330

Change-Id: I92ba7f589c8d848feb083f07c3f937b50aca388e

1 files changed, 27 insertions, 2 deletions

diff --git a/os_net_config/utils.py b/os_net_config/utils.py
index 95325a3..af359d5 100644
--- a/os_net_config/utils.py
+++ b/os_net_config/utils.py
@@ -25,6 +25,14 @@ from oslo_concurrency import processutils
 
 logger = logging.getLogger(__name__)
 _SYS_CLASS_NET = '/sys/class/net'
+# File to contain the DPDK mapped nics, as nic name will not be available after
+# binding driver, which is required for correct nic numbering.
+# Format of the file (list mapped nic's details):
+#   -
+#     name: eth1
+#     pci_address: 0000:02:00.0
+#     mac_address: 01:02:03:04:05:06
+#     driver: vfio-pci
 _DPDK_MAPPING_FILE = '/var/lib/os-net-config/dpdk_mapping.yaml'
 
 
@@ -73,6 +81,12 @@ def interface_mac(name):
         with open('/sys/class/net/%s/address' % name, 'r') as f:
             return f.read().rstrip()
     except IOError:
+        # If the interface is bound to a DPDK driver, get the mac address from
+        # the dpdk mapping file as /sys files will be removed after binding.
+        dpdk_mac_address = _get_dpdk_mac_address(name)
+        if dpdk_mac_address:
+            return dpdk_mac_address
+
         logger.error("Unable to read mac address: %s" % name)
         raise
 
@@ -176,6 +190,7 @@ def bind_dpdk_interfaces(ifname, driver, noop):
                     msg = "Failed to modprobe vfio-pci module"
                     raise OvsDpdkBindException(msg)
 
+            mac_address = interface_mac(ifname)
             try:
                 out, err = processutils.execute('driverctl', 'set-override',
                                                 pci_address, driver)
@@ -183,7 +198,7 @@ def bind_dpdk_interfaces(ifname, driver, noop):
                     msg = "Failed to bind dpdk interface err - %s" % err
                     raise OvsDpdkBindException(msg)
                 else:
-                    _update_dpdk_map(ifname, pci_address, driver)
+                    _update_dpdk_map(ifname, pci_address, mac_address, driver)
 
             except processutils.ProcessExecutionError:
                 msg = "Failed to bind interface %s with dpdk" % ifname
@@ -219,19 +234,29 @@ def _get_pci_address(ifname, noop):
 # way to identify the nic name after it is bound. So, the DPDK bound nic info
 # is stored persistently in a file and is used to for nic numbering on
 # subsequent runs of os-net-config.
-def _update_dpdk_map(ifname, pci_address, driver):
+def _update_dpdk_map(ifname, pci_address, mac_address, driver):
     contents = get_file_data(_DPDK_MAPPING_FILE)
     dpdk_map = yaml.load(contents) if contents else []
     for item in dpdk_map:
         if item['pci_address'] == pci_address:
             item['name'] = ifname
+            item['mac_address'] = mac_address
             item['driver'] = driver
             break
     else:
         new_item = {}
         new_item['pci_address'] = pci_address
         new_item['name'] = ifname
+        new_item['mac_address'] = mac_address
         new_item['driver'] = driver
         dpdk_map.append(new_item)
 
     write_yaml_config(_DPDK_MAPPING_FILE, dpdk_map)
+
+
+def _get_dpdk_mac_address(name):
+    contents = get_file_data(_DPDK_MAPPING_FILE)
+    dpdk_map = yaml.load(contents) if contents else []
+    for item in dpdk_map:
+        if item['name'] == name:
+            return item['mac_address']